BEIRUT, Lebanon (CNN) -- A United Nations peacekeeper working to clear landmines died Wednesday in southern Lebanon, according to a spokeswoman for the U.N. Interim Force in Lebanon.
U.N. peacekeepers have had a presence in Lebanon since 1978 after Israel withdrew.
The person died in an explosion as the UNIFIL explosive ordnance disposal team surveyed a field near the village of Aitaroun, where mines are believed to have been planted, according to spokeswoman Yasmina Bouziane. It was UNIFIL's second mine-related death since 2006, she said.
"UNIFIL medical and explosive ordnance disposal teams were immediately dispatched to the location and an investigation is under way," she said.
She would not disclose the person's nationality and said she hoped to have more details about how the person was killed when the investigation is completed "hopefully by tomorrow."
There are about 15,000 UNIFIL troops in southern Lebanon. The force was set up in 1978 after Israeli forces withdrew from Lebanon, but more troops were added following the 2006 war between Israel and Hezbollah forces in Lebanon.
Last week, the U.N. Security Council extended UNIFIL's mandate for another year until August 2009.
Wednesday's death is the first UNIFIL fatality since June, when a Spanish peacekeeper died in a road accident in southern Lebanon. Last year, a bomb attack hit a UNIFIL vehicle in June, killing six peacekeepers. A French peacekeeper with UNIFIL died a month later while clearing unexploded ordnance left over from the 2006 war.
While it is unclear what type of device killed the member of the explosive ordinance disposal team on Wednesday, the United Nations has warned that the area is still covered in cluster munitions from the 2006 conflict.
Last month, the head of the U.N. Mine Action Coordination Center of South Lebanon said it has removed half of the cluster munitions that were planted in southern Lebanon during the 34-day conflict between Israel and Hezbollah.
CNN's Nada Husseini in Beirut contributed to this report.